Buggy code:
public class DataAccessorWithMemcache implements DataAccessor { private static final String PREFIX_APP_PROPERTY = "AppProperty-" ; private static final String PREFIX_USER = "User-" ; private static final String PREFIX_ACCESS_TOKEN = "AccessToken-" ; private static final String PREFIX_PAGE = "Page-" ; private static final String PREFIX_PRATILIPI = "Pratilipi-" ; private static final String PREFIX_AUTHOR = "Author-" ; private static final String PREFIX_USER_PRATILIPI = "UserPratilipi-" ; private static final String PREFIX_CATEGORY = "Category-" ; private static final String PREFIX_CATEGORY_LIST = "CategoryList-" ; private static final String PREFIX_PRATILIPI_CATEGORY_LIST = "PratilipiCategoryList-" ; private final DataAccessor dataAccessor ; private final Memcache memcache ; public DataAccessorWithMemcache ( DataAccessor dataAccessor , Memcache memcache ) { } public PersistenceManager getPersistenceManager ( ) { } @ Override public AppProperty newAppProperty ( String id ) { } @ Override public AppProperty getAppProperty ( String id ) { } @ Override public AppProperty createOrUpdateAppProperty ( AppProperty appProperty ) { } @ Override public User newUser ( ) { } @ Override public User getUser ( Long id ) { } @ Override public User getUserByEmail ( String email ) { } @ Override public User getUserByFacebookId ( String facebookId ) { } @ Override public DataListCursorTuple < User > getUserList ( String cursor , Integer resultCount ) { } @ Override public User createOrUpdateUser ( User user ) { } @ Override public User createOrUpdateUser ( User user , AuditLog auditLog ) { } @ Override public AccessToken newAccessToken ( ) { } @ Override public AccessToken getAccessToken ( String accessTokenId ) { } @ Override public DataListCursorTuple < AccessToken > getAccessTokenList ( String cursorStr , Integer resultCount ) { } @ Override public DataListCursorTuple < AccessToken > getAccessTokenList ( Long userId , Date minExpiry , String cursorStr , Integer resultCount ) { } @ Override public AccessToken createOrUpdateAccessToken ( AccessToken accessToken ) { } @ Override public AccessToken createOrUpdateAccessToken ( AccessToken newAccessToken , AccessToken oldAccessToken ) { } @ Override public void deleteAccessToken ( AccessToken accessToken ) { } @ Override public AuditLog newAuditLog ( ) { } @ Override public AuditLog createAuditLog ( AuditLog auditLog ) { } @ Override public DataListCursorTuple < AuditLog > getAuditLogList ( String cursorStr , Integer resultCount ) { } @ Override public DataListCursorTuple < AuditLog > getAuditLogList ( String accessId , String cursorStr , Integer resultCount ) { } @ Override public Page newPage ( ) { } @ Override public Page getPage ( Long id ) { } @ Override public Page getPage ( String uri ) { Page page = memcache . get ( ( ( DataAccessorWithMemcache . PREFIX_PAGE ) + uri ) ) ; if ( page == null ) { page = dataAccessor . getPage ( uri ) ; if ( page == null ) { page = dataAccessor . newPage ( ) ; page . setUri ( uri ) ; } memcache . put ( ( ( DataAccessorWithMemcache . PREFIX_PAGE ) + uri ) , page ) ; } <START_BUG> return page ; <END_BUG> } @ Override public Page getPage ( PageType pageType , Long primaryContentId ) { } @ Override public Map < Long , Page > getPages ( PageType pageType , List < Long > primaryContentIdList ) { } private String createPageEntityMemcacheId ( PageType pageType , Long primaryContentId ) { } @ Override public Page createOrUpdatePage ( Page page ) { } @ Override public Pratilipi newPratilipi ( ) { } @ Override public Pratilipi getPratilipi ( Long id ) { } @ Override public List < Pratilipi > getPratilipiList ( List < Long > idList ) { } @ Override public DataListCursorTuple < Long > getPratilipiIdList ( PratilipiFilter pratilipiFilter , String cursorStr , Integer resultCount ) { } @ Override public DataListCursorTuple < Long > getPratilipiIdList ( PratilipiFilter pratilipiFilter , String cursorStr , Integer offset , Integer resultCount ) { } @ Override public DataListCursorTuple < Pratilipi > getPratilipiList ( PratilipiFilter pratilipiFilter , String cursorStr , Integer resultCount ) { } @ Override public Pratilipi createOrUpdatePratilipi ( Pratilipi pratilipi ) { } @ Override public Pratilipi createOrUpdatePratilipi ( Pratilipi pratilipi , AuditLog auditLog ) { } @ Override public Author newAuthor ( ) { } @ Override public Author getAuthor ( Long id ) { } @ Override public Author getAuthorByEmailId ( String email ) { } @ Override public Author getAuthorByUserId ( Long userId ) { } @ Override public List < Author > getAuthorList ( List < Long > idList ) { } @ Override public DataListCursorTuple < Long > getAuthorIdList ( AuthorFilter authorFilter , String cursor , Integer resultCount ) { } @ Override public DataListCursorTuple < Author > getAuthorList ( AuthorFilter authorFilter , String cursor , Integer resultCount ) { } @ Override public Author createOrUpdateAuthor ( Author author ) { } @ Override public Author createOrUpdateAuthor ( Author author , AuditLog auditLog ) { } @ Override public UserPratilipi newUserPratilipi ( ) { } @ Override public UserPratilipi getUserPratilipi ( Long userId , Long pratilipiId ) { } @ Override public DataListCursorTuple < UserPratilipi > getPratilipiReviewList ( Long pratilipiId , String cursor , Integer offset , Integer resultCount ) { } @ Override public DataListCursorTuple < UserPratilipi > getUserPratilipiList ( Long userId , Long pratilipiId , String cursorStr , Integer resultCount ) { } @ Override public UserPratilipi createOrUpdateUserPratilipi ( UserPratilipi userPratilipi ) { } @ Override public Category getCategory ( Long id ) { } @ Override public List < Category > getCategoryList ( Language language ) { } @ Override public List < PratilipiCategory > getPratilipiCategoryList ( Long pratilipiId ) { } @ Override public void destroy ( ) { } }

Fix:
return ( page . getId ( ) ) == null ? null : page ;